NeuLAND Demonstrator at SAMURAI and first experiments

The high-resolution neutron time-of-flight spectrometer with large acceptance NeuLAND is the new neutron detector being developed for the R³B setup (Reactions with Relativistic Radioactive Beams) at FAIR. NeuLAND is dedicated to the detection of high-energy neutrons up to 1 GeV. The NeuLAND Demonstrator (400 out of finally 3000 scintillator bars) is currently part of the SAMURAI setup (Superconducting Analyzer for Multi-particle from Radio Isotope Beams) at the RI Beam Factory in Japan. The machine study experiment of the NeuLAND Demonstrator is discussed in detail. In this experiment, quasi-monoenergetic neutrons were applied in order to determine the specific one-neutron detection efficiency of the detector at two different energies, in particular 110 MeV and 250 MeV. The NeuLAND Demonstrator together with NEBULA (Neutron-detection system for Breakup of Unstable-Nuclei with Large Acceptance) leads to a large multi-neutron detection efficiency at the SAMURAI experimental setup. An illustrative example applying the invariant-mass spectroscopy to neutron-unbound states of fluorine isotopes is introduced.